Individual telephone-call



(No Model.)

J. A. LAKIN.

. INDIVIDUAL TELEPHONE CALL. NO. 276,604. Patented May 1,1883.

WWW/mam %W j if gm UNITED STATES PATENT OFFICE.

JAMES A. LAKIN, OF WESTFIELD, MASSACHUSETTS.

INDIVIDUAL TELEPHONE-CALL.

SPECIFICATION forming part of Letters Patent No. 276,604, dated 1, 1883.

(No model.)

To all whom it may concern Be it known that I, JAMEs A. LAKIN, of

Westfield,inthe county of Hampden and State of Massachusetts, have invented a new and useful Improvement in Apparatus for Operating Telephone Call Signals, which has not been patented to any person in any foreign country with my knowledge or consent, and of which the following is a specification.

The object of my invention is to provide an apparatus for sounding or making an alarm at any one of a series of stations on a telephonecircuit without making an alarm at any of the other stations on the same circuit; and I accomplish this object by the apparatus illustrated in the accompanying drawings, in which Figure I is a front view of the apparatus as used at each station on a circuit, and inclosed in a box or case, and showing its connection with the line-circuit and the local circuit; and Fig. II is a modification of the circuit-closer.

1n the drawings, Fis a box or case containing the apparatus with which each station on a circuit is supplied, and A is an electro-magnet secured therein, with its armature a pivoted at 20, with a suitable spring connected therewith to hold the armature away from the magnet, an adjustingscrew, e, servingto regulate the distance to which it may be moved away from the magnet.

A metallic disk or wheel, E, is adjusted to revolve upon a metallic stud or axis, D, and a ratchet or toothed wheel, 9, is fixed to the disk. All the disks E on any one circuit are divided into as many sections or divisions as there are stations on the circuit, atone of which divisions corresponding to the number of the station is a projecting pin,as at S in the drawings-that is to say, at station 1 on the circuit the pin is at the first point or division on the disk, which may be numbered 1, if desired. At station 2 the pin is at the second point or division on the disk, and which point may be marked 2, and soon, there being as many divisions on each disk as there are stations, and the pin, at each station being at the point or division corresponding with the number of the station, and all the disks are adjusted in the same relative position. If all the divisions were numbered and there were eight divisions on each disk, and the number 8 were uppen most at one station, the same number will be uppermost at all the other stations; but only one would have the pin at the division S namely, that at station 8.

The armature (t at the magnet A has attached thereto a pawl, 7", which engages with the teeth of the ratchet 9, and operates to turn the latter and the disk E, to which it is attached, a very little when the said armature is drawn toward its magnet, a detent, c, serving to prevent the ratchet from turning in the opposite direction, or backward, when the armature and its pawl move away from the magnet.

The electro-magnet B is provided with an armature, I), pivoted at19, and has a metallic projection, 10, on its lower side, which, when the armature is away from the magnet, rests upon or isin contact with the projecting pin at one of the divisions on the disk, as at the division numbered 8 in the drawings; but this projection 10 is never in contactwith the disk itself.

A lever, 11, is pivoted at 12, one arm of which is heavier than the other, and rests on a projecting pin, 13, whenever the armature bis held up to its magnet B; but when the electro-magnet B is made inoperative the elongated end of the armature I), in falling, strikes upon and forces down the lighter arm of the lever 11 and raises its heavier end. If desirable, this heavier end of thelever may be only slightly heavier, and be provided with a rack, 25, to engage with a ,pinion,27,carrying a fan, 26, as shown clearly in Fig. II, in which case the free end of the armature I) would be longer in moving down, owing to the force necessary to be exerted in starting the fan; and in this case the projection 10, instead of being on the armature I), might be made on the lever 11, as shown clearly in Fig. II.

The armature of the magnet O is pivoted at 18, and made elastic nearits pivot, with a hellhammer attached to its upper end,and extending up through the case to a point near a bell, and a spring, 14, is secured to the case, against which the armature strikes when it moves away from the magnet 0, this arrangement of magnet, armature, and bell being the well-known vibrator used for ringing alarms.

L represents the line-circuit, extending from the ground to the screw-cup 30, thence through the magnet A, spring circuit-breaker 16, magnet 13, and screw-cup 31, to the battery I, and thence to the ground, and the line-circuit is complete when the press-button 17 is not pressed in.

H represents the local circuit, extending from the screw-cup 32 to the spring 14', and from the armature 0, through the magnet (J, to the stud or axis 1), upon which the disk E revolves, and then extends from the armature b, through the screw-cup 33, to the battery G, and from thence around to the screw-cup 32. This circuit is not complete except when the projection 10 on the armature b rests upon or is in contact with the pin in the disk, as at S in the drawings; and when it is so completed by contact of the projection and pin the electro-magnet G is made operative, and the bell will be rung by the armature as long as such contact continues.

A weighted dog, 35, is pivoted at 00, with a spring press-button, 3G, to force the lower end of the dog inward, by which movement the sharp upper end of the dog throws the armature b upward partially to its magnet B, until the sharp end of the dog passes the shoulder 0, against which it then catches, and holds the armature .in that position, sufficiently elevated to break the circuit between the projection 10 and the pin, as at 8. This press-button 36 is used by the person at the station to break the circuit H and stop the alarm when he has been called, and when the operator at the central office next presses in his press-button 17 the armature I) is drawn entirely up to the magnet, and the dog is thereby released and drops back to its place In calling the central ofl'iee the person at the station presses in the pressbutton17 once, which breaks the line-circuit L and drops the indicator at the central office, and withoutringing any hell on the circuit, so

. that a call for the central office from any station on the circuit is not known at any of the other stations.

The letter B, or some indicating character, may be stamped upon each disk on the circuit at each division on the disk; or if these divisions are numbered the letters or characters may be stamped in a circle justinside the series of numbers, and a small hole made in the door of the case, with a glass therein, will enable the person at each station to readily see that the line is in use whenever a letter 5 or indicatingcharacteris exposed to view through the glass, as in that case the projection 10 on the armature I) will be in contact with the pin in the disk at some one of the stations on the I circuit, and a call cannot be made from a station to the office without interfering with the use of the line by some other person on the circuit; but when no letter orindicating character can be seen through the glass a call can be made to the central oftice and the line he used.'

The operation of my invention is as follows: Suppose, for example, it is desired tocall station 8 on a circuit from the central office. The operator there presses in the press-button 17 of his instrument, by a succession of rather quick impulses, until the number 8 on the disk ofhis instrumentis uppermost, or is exposed to view through the aperture in the case; and although there is no pin at that division or number in his instrument, he knows there is one atstation 8 in that position, as all the disks on that circuit are adjusted precisely alike with reference to the positions of the divisions on the disks, the pins only being arranged differently. This succession of quick impulses makes the magnet A operati ve ateach impulse, causing a corresponding movement to and fro of the armature a, which gives an intermittent rotary movement to the disk E at all the stations alike, and all stop with thepoint or division 8 uppermost, the disk at station 8 having the pin at that point. This series of quick successive impulses against the pressbutton also makes the magnet B operative at all the stations, and the armature bis caused to make a corresponding number of Zovements up and down toward and from the magnet 13, although if the impulses are made very quick these movements of the armature I) will be very slight; but to make the operation more positive and obviate, as far as may be, the liability of ringing an alarm at the wrong station, and if the impulses against the press-button are slower, the armature in each downward movement strikes upon the lighter end of the lever 11, and, if properly adjusted, somewhat slowly raises the weighted end of that lever. Before the armature can do this sufficiently for the projection 10 to drop far enough to touch any of the pins in the disks at the several stations the next impulse again lifts the armature b to its magnet B, and the weighted end of the lever 11 falls, and this is repeated at every impulse, so that no armature b at any station can drop far enough to touch the pin in the disk at that station until a pauseis made in theimpulses, when the point or division 8 is uppermost, by holding in the press-button a short time, when all the armatures b will then drop at all the stations, that at station 8 raising the weighted end of the lever 1.1 sufficiently for the projection 10 to come into contact with the pin in the disk. This contact closes the local circuit and the bell at station 8 is rung, but, no other local circuit being closed in the series of stations, no other bell is run After hold-- ing in the press-button for a sufficient length of time for the bell to be rung, or after receiving a response from station 8, the operator releasing the press-button to carry the pin away from contact with the projection 10 at station 8, the apparatus is then ready to be used for another alarm.

The instrument at the central office is provided with a disk, upon which all the points of division are numbered, as shown in the drawings at 1, 2, 3, &c.; but no projecting pins are necessary in that disk, as all that is required at the central ottice is for the operator to make the impulses against the press-button until he brings the required number on his disk uppermost, when he knows that the pin at the station he is calling will be in position then for the alarm to be given. It is not necessary, however, for any of the disks at the out-stations on the circuit to be numbered, as all that is required is a projecting pin in the disk, with which to make contact with thearinature b, and if the out-station disks are not numbered, of course no person on the circuit will know what his neighbors number is, and as no bell is ,rung except that at the station called, the others will not know when a call is being made, and the chance for eavesdropping is very much lessened.

It is evident that the pin or projection, as at 8, instead of projecting out at right angles to the face of the disk E, may project outward and upward toward the armature, so that the latter, when it dropped, would touch the projecting pin, but would not touch the disk at any point.

Having described my invention,whatIclaim as new isl. The combination, with a main-line electric circuit, of a local circuit, a metal disk adapted to rotate on its axis, and included in said local circuit, and provided with a projecting pin and a ratchet, an electro-magnet included in the main line, whose armature is provided with a pawl to engage with and intermittently rotate said ratchet and disk by the movements of said armature, an electromagnet included in the main line, and whose armature is included in said local circuit, and is adapted to drop into electric connection with said disk when the main-line circuit is held broken, substantially as described.

2. The combination. with a main-line electric circuit, of a local circuit, a metal disk adapted to rotate on its axis, and included in said local circuit, and provided with a projecting pin and a ratchet, an electro-magnet included in the mainline, whose armature is provided with a pawl to engage with and intermittently rotate said ratchet and disk by the movements of said armature, an electro-mag net included in the main line, and whose armature is included in said local circuit, and is adapted to drop into electric connection with said disk when the main-line circuit is held broken, and an electro-magnet and its armature ,.or vibrator included in the local circuit, sub

stantially as described.

JAMES A. LAKIN. Witnesses:

T. A. CURTIS, F. E. HALL. 

